Transplant surgery is now used routinely in cases where patients have body organs that are damaged or malfunctioning. For example heart, lung, liver and kidney transplants are all well known. In transplant surgery, the patient's organ is removed and replaced with an organ donated by a donor. It is often necessary to transport a donated organ from the place of donation to the location of the transplant surgery. This can often involve transport of the donated organ over long distances. A donated organ in transit will be isolated from a blood supply and is therefore subject to ischaemic damage. It is important to limit this ischaemic damage, as any damage may affect the functioning of the organ after it has been transplanted.
It is also now common to perform surgery where an in situ body organ, tissue or part is isolated from the patient's blood supply. An example of this is heart valve replacement where the heart is stopped by a cardioplegic solution and the function of the heart is taken over by a mechanical pump system located outside of the body. In this case, the heart is isolated from the patient's blood supply. Again, there is a risk that an organ isolated in such a manner could be affected by ischaemic damage which is undesirable.
The beneficial physiological effects of carbon monoxide (CO) have been recognized and reported in a number of publications. A discussion of the background studies carried out in this area are reported in co-pending application WO 02/092075 published 21 Nov. 2002 which originates from work of the present inventors.